In retrospect I think it was an error on my part to include contained in which has clearly nothing to do with the rest. Thank you for your answer. I hope others will provide feedback too. Otherwise it'll be a bit hard for me to say if it's correct or not.
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musiKkMay 20 '11 at 13:00

Even I won't gnash my teeth at you. "Comprised of" is arising from an error (like irregardless), and even if it could one day become an accepted standard (which it certainly could), at the moment you risk appearing as though you have a poor command of the finer points of English if you use this construction.
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KosmonautMay 20 '11 at 14:01

Unfortunately this question didn't get as much attention as I hoped. Or maybe this answer sums it up best? Anyway, I'll accept it because it's certainly useful.
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musiKkMay 24 '11 at 9:07

There are some works relating the relatively mature field of mereology to natural languages; Wikipedia barely mentions them. I am not an expert on this particular crossroads, but I'm afraid that the ambiguity of natural language won't let you find hard and fast rules as you request. "Parts: A Study in Ontology" by Simons 1987 is the work that I know best about this, and you may find it useful if you are interested in a detailed study of the matter.